US3930170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching transistor drive apparatus
Assignee: ITT Inc
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Filing: 1974-06-04
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Granted: 1975-12-30
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Expires: 1994-06-04
Abstract
Abstract Switching transistor drive apparatus having a first transistor for receiving a signal condition, a resistance, capacitor and transformer primary for charging the capacitor when the transistor is saturated and for discharging the capacitor when the transistor is OFF, a relationship of the primary and in-phase relationship of secondaries to saturate and regeneratively saturate a second transistor, and turn-off operation of the second transistor when a positive pulse is applied to the base of the first transistor. One alternate embodiment enables circuit operation at higher currents by utilizing a switchable impedance network for said resistance. Another alternative approach decreases the fall time of the second transistor by the addition of a resistor-diode network connected from base to emitter of the second transistor.
Inventors
- 👤 James H Burens
- 👤 Kenneth A Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:22
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04126; H03K17/042; H03K17/0424; H03K17/12; H03K17/51; H03K17/56; H03K17/60; H03K17/601
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
173 words
In a switching transistor drive apparatus, a first transistor having a base, a collector and an emitter, a second transistor having a base, a collector and an emitter, a transformer having a primary N1, and secondaries N2 and N3 forming windings of a larger and a smaller number of turns, respectively, for the transformer, first resistance means connecting a source to the collector of the first transistor, an impedance network connecting the collector of the first transistor to a terminal of the primary N1, the other terminal of the primary N1 connected to the emitter of the first transistor and to a return connection of said source, a common terminal for secondAries N1 and N2 connected to the emitter of the second transistor, the secondaries N2 and N3 wound and connected in series aiding relationship so that said secondary of larger number of turns has its other terminal connected to the base of the second transistor and so that the secondary of smaller number of turns has its terminal connected to a load.
Claim 2
Dependent Claim
173 words
In a switching transistor drive apparatus, a first transistor having a base, a collector and an emitter, a second transistor having a base, a collector and an emitter, a transformer having a primary N1, and secondaries N2 and N3 forming windings of a larger and a smaller number of turns, respectively, for the transformer, first resistance means connecting a source to the collector of the first transistor, an impedance network connecting the collector of the first transistor to a terminal of the primary N1, the other terminal of the primary N1 connected to the emitter of the first transistor and to a return connection of said source, a common terminal for secondAries N1 and N2 connected to the emitter of the second transistor, the secondaries N2 and N3 wound and connected in series aiding relationship so that said secondary of larger number of turns has its other terminal connected to the base of the second transistor and so that the secondary of smaller number of turns has its terminal connected to a load.
Claim 3
Dependent Claim
18 words
The invention of claim 1 wherein said impedance network is a parallel arrangement of a capacitor and diode.
Claim 4
Dependent Claim
58 words
The invention of claim 1 having means wherein as the second transistor begins to conduct, the current in secondary N3 is reflected into secondary N2, further increasing the base current until saturation of the second transistor occurs, and wherein during saturated operation of the second transistor, the base current thereof is due to that current reflected by N3.
Claim 5
Dependent Claim
115 words
The invention of claim 1 wherein said first resistance means is an impedance network including a third transistor coupled between said source and the collector of the first transistor, a further resistor intercoupled between said source and a collector of a fourth transistor, an emitter of the fourth transistor connected to the base of the first transistor, a further resistance coupled between the base and the emitter of the first transistor, a connection between the base of the third transistor and the collector of the fourth transistor, a diode connected between the collector of the fourth transistor and the collector of the first transistor, and a resistor connected between the source and the third transistor.
Claim 6
Dependent Claim
45 words
The invention of claim 1 wherein the base circuit of the second transistor has a means active during turn-off consisting of three series diodes arranged in a blocking configuration during conduction of said transistor and a resistor connected in parallel with one of said diodes.
Claim 7
Dependent Claim
46 words
The invention of claim 4 wherein the base circuit of the second transistor has a means active during turn-off consisting of three series diodes arranged in a blocking configuration during conduction of said transistor and second resistance means connected in parallel with one of said diodes.
Claim 8
Dependent Claim
127 words
In a switching transistor drive apparatus a switching transistor for providing power from a source to a load whenever said switching transistor is forward biased, a multi-winding current transformer having a primary winding, a base winding and a feedback winding, a switching means including a second source from which current flows through a series connection of a resistor, a capacitor and said primary winding for forward biasing said switching transistor, said base winding coupling said switching means to said switching transistor, said feedback winding providing regenerative base current for the forward biased switching transistor, and a turn-off means consisting of a control transistor which when enabled causes a reversal of current flow in the said primary winding and therefore in said base winding of said current transformer.
Claim 9
Dependent Claim
127 words
In a switching transistor drive apparatus a switching transistor for providing power from a source to a load whenever said switching transistor is forward biased, a multi-winding current transformer having a primary winding, a base winding and a feedback winding, a switching means including a second source from which current flows through a series connection of a resistor, a capacitor and said primary winding for forward biasing said switching transistor, said base winding coupling said switching means to said switching transistor, said feedback winding providing regenerative base current for the forward biased switching transistor, and a turn-off means consisting of a control transistor which when enabled causes a reversal of current flow in the said primary winding and therefore in said base winding of said current transformer.
References Cited (Backward Citations)
US3657569A
Cited
US3610963A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |